1. Field of the Invention
The invention, according to various exemplary embodiments, relates to high-frequency power amplifiers and operational parameters thereof.
2. Discussion of the Background
In the operation of high-frequency power amplifiers, for example, a transistor power output stage of a variable-frequency shortwave transmitter, it is necessary to measure various operational parameters at an output of the power amplifier. For this purpose, the measurement on a connecting line between the output of the power amplifier and a complex load such as an antenna, for example, by one or more directional couplers, of a forward voltage proportional to a forward wave and a return voltage corresponding to a returning, reflected wave, by one or more directional couplers, is known from DE 27 10 752 A1 and respectively DE 39 18 159 A1. From these analog voltages measured in a high-frequency (HF) position, a required operational parameter of the amplifier is then calculated generally with an analog circuit. One disadvantage of the known arrangements is that, as a result of the determination of the measured values at the HF level, the calculations are relatively costly and complex, even if these calculations are implemented digitally.